This invention relates generally to the field of mail box signals of the type disclosed, for example, in U.S. Pat. No. 2,480,469, granted Aug. 30, 1949 to C. P. Horn, and more particularly to an improved form thereof in which prior art disadvantages have been substantially eliminated.
The current state of the art has reached a currently high degree of development, consistent with changes in delivery by post office personnel. The traditional rural mail box includes a side mounted signal flag which can be raised to erected condition by the postman to indicate delivery. However, delivery at the present time is usually made without alighting from a vehicle, and the flag, being mounted along a side wall, is not always available to the postman, as is the end mounted door of the box.
The problem has been a long standing one. The Morrow U.S. Pat. No. 812,514 of Feb. 13, 1906 discloses an early attempt to resolve this difficulty. Unfortunately, the signal erection means requires the cutting of the side wall of the mail box to expose delivered mail to the elements.
The Smith U.S. Pat. No. 1,973,020, of Sept. 11, 1934 pivotally mounts a small flag to the rear side wall of the box, operated by an elongated wire linkage. With continued exposure to the elements, the linkage rusts to the point where it is no longer serviceable.
The above mentioned Horn patent substitutes an equally rustable coil spring for the linkage of Smith, with the same accompanying disadvantage.
The McMinn U.S. Pat. No. 2,849,176 of Aug. 25, 1958 employs a pair of elongated coil springs which control the opening and closing of the door of the mail box past a center point, the door including a flag which is raised period. Unfortunately, the position of the flag is not readily visible from all sides.
The Harger U.S. Pat. No. 2,954,920 of Oct. 4, 1960 includes a gravity mounted flag which disappears with the opening of the mail box so that the resetting of the same is sometimes forgotten by the user.
The Wing U.S. Pat. No. 3,034,706 of May 15, 1962 employs a pivotally mounted flag actuated by a coil spring disposed in the interior of the mail box.
The Joris U.S. Pat. No. 4,073,430 of Feb. 4, 1978 employs a disconnectible wire attached to a bracket on the inner surface of the door of the mail box. The wire must be manually reengaged with each cycle of operation, difficult in cold weather.
The Mapes U.S. Pat. No. 4,150,780 of Apr. 24, 1979 employs a side mounted signal operated by a stiff wire extending across the front of the mail box door.
All of the above constructions include parts which are subject to deterioration with continued exposure to the elements, and many are so flimsy as to preclude extensive use.